Answer:
C. Nucleotides
Explanation:
Nucleic acids are macromolecules which are polymers of nucleotides. There are two types of nucleic acids namely: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleotides are the building blocks of nucleic acids.
A nucleotide is made up of three components:
- A phosphate group
- A five carbon sugar called pentose sugar. In RNA the sugar is ribose sugar and in DNA the sugar is deoxyribose sugar.
- Nitrogenous bases: There are four different types of bases in DNA: adenine, guanine, cytosine and thymine. In RNA thymine is replaced by uracil. Adenine and guanine are purines whereas cytosine, thymine and uracil are pyrimidines.
Nitrogenous base and sugar together are called nucleoside and when phosphate is also attached then it is called nucleotide.
Answer: Soil is the earthworm's habitat.
Explanation: The worm gets the food from the soil and also lives in to soil, that is the basic living needs for a habitat.
Answer:
Absorption and secretion would be impossible within the digestive tract.
Explanation:
Epithelium is one of the tissues found in humans. It is classified as either simple or stratified depending on the number of cell layers. Simple epithelial tissues have one layer of cells while stratified have many layers of cells. Based on the shape, epithelial tissues can either be squamous, columnar or cuboidal.
Due to the single-layer of the simple epithelial tissues, they line the walls of secretory or absorptive organs e.g organs of digestive tract. The stratified epithelium is majorly for protective function due to the number of cell layers it possess and not a good type of epithelium for locations where absorption and secretion of substances is common e.g digestive tract.
Hence, if a genetic mutation causes a person's digestive tract to have stratified columnar epithelium instead of simple columnar epithelium, ABSORPTION AND SECRETION of chemical substances, which is a key feature of organs (stomach, intestine) that make up digestive tracts, will be impossible.
Symbiosis is the relationship of 2 organisms. The 3 major types are commensalism, mutalism, and parasitism. Hope that this helps!
